CARACAS, Venezuela — President Hugo Chávez, buffeted by falling oil prices that threaten to damage his efforts to establish a Socialist-inspired state, is quietly courting Western oil companies once again.

President Hugo Chávez is expected to put forth a referendum this year that would let him run for indefinite re-election.

Social programs like food subsidies, which these women in Caracas picked up, are financed by Petróleos de Venezuela’s profits.

Until recently, Mr. Chávez had pushed foreign oil companies here into a corner by nationalizing their oil fields, raiding their offices with tax authorities and imposing a series of royalties increases.

But faced with the plunge in prices and a decline in domestic production, senior officials have begun soliciting bids from some of the largest Western oil companies in recent weeks — including Chevron, Royal Dutch/Shell and Total of France — promising them access to some of the world’s largest petroleum reserves, according to energy executives and industry consultants here.

Their willingness to even consider investing in Venezuela reflects the scarcity of projects open to foreign companies in other top oil nations, particularly in the Middle East.

But the shift also shows how the global financial crisis is hampering Mr. Chávez’s ideological agenda and demanding his pragmatic side. At stake are no less than Venezuela’s economic stability and the sustainability of his rule. With oil prices so low, the longstanding problems plaguing Petróleos de Venezuela, the national oil company that helps keep the country afloat, have become much harder to ignore.

Embracing the Western companies may be the only way to shore up Petróleos de Venezuela and the raft of social welfare programs, like health care and higher education for the poor, that have been made possible by oil proceeds and have helped bolster his popular support.

“If re-engaging with foreign oil companies is necessary to his political survival, then Chávez will do it,” said Roger Tissot, an authority on Venezuela’s oil industry at Gas Energy, a Brazilian consulting company focusing on Latin America. “He is a military man who understands losing a battle to win the war.”

While the new oil projects would not be completed for years, Mr. Chávez is already looking beyond the end of his current term in 2012 by putting forward a referendum, expected as early as next month, that would let him run for indefinite re-election.

In recent years, Mr. Chávez has preferred partnerships with national oil companies from countries like Iran, China and Belarus. But these ventures failed to reverse Venezuela’s declining oil output. State-controlled oil companies from other nations have also been invited to bid this time, but the large private companies are seen as having an advantage, given their expertise in building complex projects in Venezuela and elsewhere in years past.

The bidding process was first conceived last year when oil prices were higher but Petróleos de Venezuela’s production decline was getting impossible to overlook. Still, the process is moving into high gear only this month, with the authorities here expected to start reviewing the companies’ bidding plans on new areas of the Orinoco Belt, an area in southern Venezuela with an estimated 235 billion barrels of recoverable oil. Altogether, more than $20 billion in investment could be required to assemble devilishly complex projects capable of producing a combined 1.2 million barrels of oil a day.

Mr. Chávez’s olive branch to Western oil companies comes after he nationalized their oil fields in 2007. Two companies, Exxon Mobil and ConocoPhillips, left Venezuela and are still waging legal battles over lost projects.

But Venezuela may have little choice but to form new ventures with foreign oil companies. Nationalizations in other sectors, like agriculture and steel manufacturing, are fueling capital flight, leaving Venezuela reliant on oil for about 93 percent of its export revenue in 2008, up from 69 percent in 1998 when Mr. Chávez was first elected.

In the past year, with higher oil prices paving the way, Mr. Chávez also vastly expanded Petróleos de Venezuela’s power, inextricably linking it to his political program. He directed the oil company to build roads, import and distribute food, build docks and shipyards and set up a light-bulb factory. He even expanded it into areas like milk production, soybean farming and the training of athletes after a weak performance at the Beijing Olympics.

One of the oil company’s ventures sells subsidized food and extols Mr. Chávez’s leadership at its stores across Venezuela. At one frenzied store in eastern Caracas, posters hung from the ceiling last Saturday showing Mr. Chávez arm in arm with children beneath the heading, “fortifying agrarian socialism.”

Petróleos de Venezuela has also carried out nationalizations in other industries, absorbing companies like Electricidad de Caracas, the utility serving this city of five million. Top executives like Eulogio del Pino, the Stanford-educated vice president for exploration and production, spent much of 2008 negotiating unfinished deals like the takeover of a cement company.

But all the while, Petróleos de Venezuela has faced its own difficulties. It claimed it produced about 3.3 million barrels a day throughout most of 2008. But other sources, like OPEC, of which Venezuela is a member, place the figure closer to 2.3 million and show a fall of about 100,000 barrels a day from a year earlier. When Mr. Chávez rose to power a decade ago, Venezuela was producing about 3.4 million barrels a day.

Rafael Ramírez, the energy minister and president of Petróleos de Venezuela, did not respond to requests for an interview. But energy executives here with contacts within Petróleos de Venezuela said Mr. Ramírez, a confidant of Mr. Chávez, has been waging a struggle within the company to refocus operations toward producing more oil.

After weathering the turmoil of recent years, Western oil companies here are loath to speak publicly about their plans. “We don’t elaborate on bidding processes beyond the fact that we evaluate every opportunity and our decisions will be based on economics and other factors,” said Scott Walker, a spokesman for Chevron.

But energy executives here speak with restrained optimism. Nineteen companies paid $2 million each last month for data on areas open for exploration, twice what such data costs elsewhere.

Oil companies say they recognize the risk of investing in Venezuela, given the country’s abrupt shifts in the past. But they focus on the long-term potential of its petroleum reserves. Venezuela poses little risk in the search for oil since geologists have known for years where it lies in the Orinoco Belt.

Venezuela also differs from top oil nations like Saudi Arabia and Mexico, where national oil companies have monopolies. Petróleos de Venezuela let private companies remain as minority partners after the nationalizations, despite Mr. Chávez’s often aggressive anticapitalist stance.

Moreover, foreign oil services companies like Halliburton, which has done business in Venezuela for 70 years, have even expanded their activities in the country as Petróleos de Venezuela grew more dependent on contractors to help extract oil from aging wells.

Still, doubts persist over the chances that the new bids, which are set to conclude in June, will ultimately result in finished oil projects. Risks of operating here were underscored again last week when Venezuela ordered new production cuts along with other OPEC members, impacting ventures with private partners.

Under the current bidding rules, the onus for financing the new projects lies with the foreign companies, even though Petróleos de Venezuela would maintain control. Banks might balk at such a prospect. Distrust also lingers in dealing with Petróleos de Venezuela.

“An agreement on a piece of paper means nothing in Venezuela because of the way Chávez abruptly changes the rules of the game,” said a Venezuelan oil executive who has had dealings with oil companies from China, Russia and other countries.

“In 10 years, not one major oil project has been built in Venezuela,” said the oilman, who asked not to be identified for fear of retribution. “Chávez has left his so-called strategic partners out to dry, like the Chinese, who have been given the same treatment as Exxon.”

But the severity of the drop in oil prices may ultimately dictate the terms on which Venezuela re-engages with foreign oil companies.

“Chávez is celebrating the demise of capitalism as this international crisis unfolds,” said Pedro Mario Burelli, a former board member of Petróleos de Venezuela. “But the irony is that capitalism actually fed his system in times of plenty,” he said. “That is something Chávez will discover the hard way.”